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

Annotations already declare readOnly, idempotent, openWorld and non-destructive, so the safety bar is covered; the description adds two things they do not: that the call is free / never charges, and that it will resolve places this server has not seen before. That cost and coverage context is genuinely useful. It does not address rate limits or lookup failure behavior, keeping it short of 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?

The content is short, but it is delivered as choppy fragments and states the free-of-charge fact twice ('Free.' and 'This call never charges.'), which is a wasted sentence. Front-loading of the core purpose is good, but the redundant cost line costs it a point.

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?

An output schema exists, so return values need not be explained, and annotations cover the safety profile. Combined with cost transparency and the unknown-place behavior, an agent has enough to call this correctly; only the relationship to resolve_area is left 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 description coverage is 100%, so q/text/country/prefer_area are already documented in the schema; baseline is 3. The description adds a small amount of meaning for prefer_area (metropolitan area for radius searches) and an example ('UK' means the United Kingdom), but does not explain the q/text aliasing or how country is combined with text beyond what the schema says.

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 and resource: converts free text into numeric location ids for people search, and notes it works even for places the server has not seen before. That distinguishes it from list-style siblings, but it never names its closest sibling resolve_area or explains the division of labor, so sibling differentiation is only implicit.

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 one piece of conditional guidance — set prefer_area when the caller needs the metropolitan area for a radius search — and notes the call is free, which affects whether to use it liberally. However there is no explicit when-to-use / when-not-to-use against resolve_area or check_candidates, so guidance stays implied.

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