Canada Climate Observations MCP

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

With no annotations, the description must carry the behavioral load. It does disclose three useful traits: a fixed 7-day window, a hard 5-station ceiling, and that the endpoint is 'PRO' (i.e. gated behind a subscription token, consistent with the access_token parameter). It does not disclose the return shape, ordering, pagination, or what happens if more than 5 ids are supplied.

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?

Two short sentences with the capability front-loaded and the prerequisite attached to the parameter it concerns. The leading 'PRO.' is a compact tier signal, though slightly cryptic on its own.

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?

For a two-parameter read tool with no output schema and no annotations, the description covers the window, the cap, and the id source, which is most of what an agent needs. It still leaves the shape of the comparison result and the failure mode for over-limit or premium-denied requests unstated.

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 50%: access_token already has a description, but station_ids is bare in the schema. The description compensates by telling the agent where the ids come from (nearest_station) and how many are permitted (up to 5), which is the actionable semantics for the undocumented required parameter.

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 concrete verb-and-resource: returns the last 7 days of observations across a set of climate stations, with the cardinality cap of 5. It does not explain what the 'compare' aspect produces (side-by-side series vs. per-station blocks), and its differentiation from sibling daily_history is left implicit, but the scope is clear enough to select it.

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 parenthetical 'pass station ids from nearest_station' establishes a prerequisite workflow and the 'up to 5' cap sets a usage bound. However, it never says when to pick this over daily_history, which is the sibling most likely to be confused with it (same observations, different aggregation/window).

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?

With no annotations, the description carries the burden alone; it does disclose the 90-day ceiling and, via 'PRO', an implicit paid-tier/access_token requirement. It omits units (C/F, mm/in), what happens for days beyond 90 or missing data, and the response shape, which matters for an unflagged read tool.

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 efficient sentence covering data content, granularity, and window, with the scope limit front-loaded. The opaque 'PRO.' prefix spends a leading position on a label the agent cannot decode.

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?

For a 3-parameter tool with no annotations and no output schema, the definition should say more about units, the default/behavior of `days`, and auth expectations. What is present is accurate but leaves an agent guessing on several call-shaping details.

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 only 33%, so the description must compensate. 'Up to 90 days' implies the upper bound for `days` and 'for a climate station id' ties to `station_id`, but the default for `days` and how to source a valid station id are not stated; only `access_token` is documented in the schema.

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 concrete resource (daily max/min/mean temperature and precipitation) scoped to a climate station id with a 90-day window, which an agent can match to a historical-weather need. Siblings (compare_stations, nearest_station) are obviously different operations, so no disambiguation is needed, but the leading 'PRO.' token is unexplained and slightly muddies the opening.

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?

No explicit when-to-use or when-not-to-use guidance beyond the implicit 90-day cap. The description does not mention nearest_station as the way to obtain a station_id, nor compare_stations as the alternative for multi-station comparisons, leaving routing 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?

With no annotations, the description carries the full behavioral burden. It discloses that the tool is free and describes the returned observations (last 3 daily max/min/precip), but it omits permissions, error behavior for invalid postal codes, units, and whether the call is read-only.

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 a single front-loaded sentence with no wasted words. It states cost, action, input scope, and return content efficiently.

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?

For a simple lookup tool with no output schema, the description covers the core action and return contents. However, it leaves out units, output structure, and error behavior, which an agent may need to interpret results 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 0%, so the description must compensate. It adds that the input is a Canadian postal code, which is useful beyond the bare string type, but it does not specify formatting, case, spacing, or validation rules.

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: finding the nearest Environment Canada climate station to a Canadian postal code, and it also says it returns the last 3 daily observations. It does not explicitly differentiate itself from the sibling tools compare_stations and daily_history, so it falls short of a 5.

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?

There is no explicit guidance on when to use this tool versus compare_stations or daily_history, nor any exclusions or prerequisites. Usage is only implied by the tool's purpose.

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