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

Beyond the annotations, the description adds concrete behavioral context: pricing ($0.01/call via x402 USDC or card key), a free tier (first 25 free), failed calls free, and the critical note that repeats are not free because each call is charged. This directly clarifies the idempotentHint=false annotation and makes the cost model transparent, which annotations alone do not provide.

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 primary purpose and use cases, and each sentence carries useful information (source, return fields, example, pricing, read-only note). It is slightly longer than strictly necessary but no sentence is 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?

Given no output schema, the description enumerates the returned fields (coordinates, description, country, administrative region, population, elevation). Combined with the usage guidance and cost model, it provides everything an agent needs to select and invoke 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%, so both parameters are already documented in the schema. The description adds an example ('name=Uppsala') but does not explain the count parameter or add syntax details beyond the schema, so it meets the baseline without exceeding it.

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 ('Find places by name') and resource ('places in Wikidata') and lists exactly what data is returned (coordinates, description, country, administrative region, population, elevation). It distinguishes itself from siblings by naming weather, sun, and distance lookups as downstream tools, so an agent can tell it apart without inspecting the 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?

It explicitly says when to use it ('Use before weather, sun or distance lookups, or to tell two places of the same name apart') and names relevant sibling tools. It does not give explicit when-not-to-use guidance or a full decision tree against non-named alternatives, but the context is clear enough.

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