Casafari Location Lookup

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

Annotations already declare readOnlyHint, idempotentHint and openWorldHint=false, so the safety profile is covered. The description adds real context beyond that: the response surface (plan, units, callability, payment link) and the fact that the call is free, which matters for an agent deciding whether to poll it.

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?

A single sentence with no filler; the most decision-relevant facts (can calls be made now, and what to do if not) are packed in without preamble. Every clause carries information.

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 does the job of describing the return payload, which it does adequately. Minor gaps remain (no mention of caching/rate behavior or what 'remaining units' is measured in), but for a zero-parameter, read-only status tool this is close to complete.

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?

The tool takes zero parameters, so per the baseline there is nothing for the description to clarify beyond the trivial empty schema. No parameter guidance is needed or given.

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 names a specific resource (this account) and enumerates exactly what it reports: plan, remaining units, whether calls are possible, and a payment link when they are not. There are no sibling tools to disambiguate from, and the scope is unambiguous.

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?

Usage is only implied: the mention of 'whether calls can be made now and, when they cannot' hints that this is a pre-flight check before invoking other work, but the description never says when to call it or what to do with the result. With no alternatives in the toolset this is acceptable, but no explicit guidance is given.

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 readOnlyHint=true and openWorldHint=false, so the safety profile is covered. The description adds genuine behavioral value by disclosing the return shape: parent chain ordering (root first), alternate names, and whether children exist. It omits error/not-found behavior and how lang affects the returned names.

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?

A single tight sentence that front-loads the core action ('One location by id') before the secondary detail about the payload. Every clause earns its place; nothing is padded.

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 usefully compensates by characterizing the returned structure, which is the main thing an agent needs here. A small gap remains around failure modes and whether the parent chain is complete to root, but for a simple read-by-id tool this is close to sufficient.

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%, so both parameters are already documented, including the lang fallback behavior. The description alludes to 'its other names' (hinting at lang/multilingual output) but adds no syntax or constraint beyond the schema. 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?

The description states a specific verb and resource ('One location by id') and goes further by enumerating what comes back (parents root-first, other names, has-children flag). It contrasts implicitly with locations_search by emphasizing lookup by id, but never names that sibling 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?

Usage is implied: use this when you already have a location_id, versus locations_search when you don't. There is no explicit when-to-use/when-not statement or direct reference to the sibling tool, so the agent must infer the routing.

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, and closed-world behavior, so the bar is lower. The description still adds non-obvious operational context: the call is free, ids are the key other tools consume, and postcode coverage is partial by country (Spain full, France partial, Portugal only parts of Lisbon, others unsupported). It does not discuss result ordering beyond what the schema states for postcode.

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 tight sentences with no filler: purpose and return shape first, then the key id-consumption rationale, then the coverage caveat that most affects tool selection. The postcode-coverage caveat is front-loaded at the top level rather than buried in the parameter, which is the right call for a decision-affecting constraint.

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 return-value burden and does so ('their ids and parent chain'). Combined with the coverage limits, the free-cost note, and full schema coverage of all six parameters, an agent has everything needed to invoke it 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%, so every parameter including lang, size, country, postcode_match, and the query/postcode mutual requirement is already documented in the schema. The description only restates the query-vs-postcode duality and postcode coverage, adding little syntax or format detail beyond the structured fields. 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?

Names a specific verb (find) and resource (locations), enumerates the supported place levels, and states the two lookup modes (name/alias, postcode) plus what is returned (ids and parent chain). It also positions itself against siblings with 'The ids are what every other tool takes', so an agent knows this is the prerequisite lookup tool rather than one of the area-insights tools.

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 clear context for when to reach for it (you need location ids, or you have a postcode) and discloses the 'Free' cost, which helps the agent choose it over costlier alternatives. It stops short of explicit when-not-to-use guidance or naming a sibling alternative, so it is clear but not fully routing.

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