UK Fitness Pro

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare readOnly, idempotent, non-destructive and open-world, so the safety profile is covered. The description adds genuine behavioral detail beyond that: it returns up to 5 candidates ranked best-first, and includes county/region where known. It stops short of covering latency or failure behavior for unresolvable queries, so not a 5.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Three sentences, each doing distinct work: what it returns, when to use it, and where the result goes next. Front-loaded with the capability rather than burying it behind preamble.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

With no output schema, the description carries the burden of describing return values and does so: up to 5 candidates, best-first ordering, county/region included. Combined with the downstream handoff instruction, an agent has everything needed to call and use this tool correctly.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

There is a single parameter with 100% schema description coverage including examples ('Newport', 'Shoreditch', 'BS1'). The description reinforces the accepted input domain (place name or postcode) but adds no syntax or format rules beyond what the schema already states, so the baseline 3 applies.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

States a specific verb (resolve) and resource (UK place name or postcode) plus the outputs produced (coordinates and matching search page). This is clearly distinguishable from siblings like search_trainers and get_trainer_profile, which operate on trainers rather than locations.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

Gives an explicit trigger ('when a place name is ambiguous (there are many Newports)') and an explicit next step ('pass the chosen latitude/longitude to search_trainers'). The handoff to a named sibling tool leaves nothing to inference.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Beyond the read-only and idempotent annotations, the description discloses important behavioral caveats: qualifications and insurance are self-reported and must be repeated as such, and 'verified' only means identity documents were checked. It also states that phone and email are unavailable and directs users to the enquiry form, which is valuable operational context.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is front-loaded with the core purpose and then provides return fields, caveats, and contact limitations in a logical order. It is somewhat long, but nearly every sentence adds useful guidance rather than repeating structured fields.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

There is no output schema, so the description appropriately lists the returned profile fields and explains important interpretation caveats around qualifications, insurance, and verification. Together with the clear parameter guidance and annotations, it gives an agent enough to call and interpret the tool correctly.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100% and the single username parameter is already documented in the schema. The description adds meaningful semantics by explaining that the username comes from search_trainers or the last segment of a profile URL, with an example URL format.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description states a specific verb and resource: get the public profile of one personal trainer by username. It also distinguishes this from the sibling search_trainers tool by explaining that the username comes from search results or a profile URL.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

It clearly explains how to obtain the username from search_trainers or a profile URL, which gives strong usage context. It does not explicitly state when not to use this tool, but the single-profile scope is unambiguous.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare readOnly, idempotent, non-destructive and open-world, so safety is covered. The description adds value beyond them: it discloses the return payload (titles, short summaries, links) and the empty-query fallback behavior — both things annotations cannot express and that matter since there is no output schema.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Three short sentences with the core purpose front-loaded and no filler. 'Some written by trainers listed on the site' is mildly tangential but does hint at cross-linking with trainer content, so it is not wasted.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

With only two optional parameters, full schema documentation and no output schema, the description supplies what structured data cannot: the return shape and the zero-argument behavior. It is close to complete for a simple search tool; only query-strategy guidance is missing.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is 100%, with both the limit cap/default and query examples already documented in the schema. The description adds only the no-query case, which the schema does not state, but says nothing about limit semantics. Baseline 3 is appropriate.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

States a specific verb (search) and a clearly bounded resource (fitness, training and nutrition articles on UK Fitness Pro), plus what is returned. The sibling tools operate on entirely different resources (trainers, locations), so an agent can discriminate without opening the schema, though no sibling is named explicitly.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description covers one usage case well — 'With no query, returns the latest articles' tells the agent that an empty call is valid and browsing-style. It gives no guidance on when to prefer this over search_trainers/get_trainer_profile, or on how to phrase queries, so usage is only implied.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Goes well beyond annotations (readOnly/openWorld/idempotent) by disclosing the return radius, nearest-first ordering, and the important caveat about what 'verified' does and does not mean, including that most trainers are unverified and free listing means absence of a badge is not negative. It also flags that geocoding can resolve to the wrong place and how to recover.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Front-loaded with purpose and the core location/online usage decision, and the closing 'verified' explanation, while long, earns its place by preventing misreading of result badges. Slightly dense with caveats that could be trimmed.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

No output schema exists, yet the description covers return shape (links to profiles and the full results page) and result ordering. Combined with the 100% schema coverage and rich annotations, an agent has everything needed to call this correctly.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is 100%, so the baseline is 3; the description adds value by explaining the location/online alternatives and the latitude/longitude fallback as an error-recovery path. It does not add much on gender, speciality, limit, or sort beyond what the schema already states.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

Opens with a specific verb and resource ('Find personal trainers listed on UK Fitness Pro') and immediately scopes it to a UK directory with a stated ~12 mile radius. An agent can distinguish this from get_trainer_profile, find_location, and search_articles without opening any schema.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

Explicitly routes between alternatives: `location` vs `online: true`, get_trainer_profile for description/qualifications/pricing, and find_location when the resolved location is wrong. These are concrete when-to-use conditions tied to named siblings.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.