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

Annotations already declare readOnlyHint and openWorldHint, so the safety profile is covered. The description adds real behavioral value beyond that: results are distance-ordered and come from a stored users dataset rather than a live crawl, which tells the agent what kind of data to expect.

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 sentences, purpose front-loaded, and each sentence earns its place: the first defines the action and ordering, the second gives the usage trigger and data provenance. No filler or redundancy.

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 an output schema present the description needn't explain return values, and annotations cover safety, so the remaining burden is light. It adequately covers purpose, ordering, source, and usage; the optional filter parameters are left entirely to the schema, which is acceptable given full coverage.

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 the schema already documents lat, lon, radius_m, pagination and the reachable/min_followers/influence_tier filters. The description only restates the lat/lon proximity concept and adds no format, unit, or filter semantics beyond the schema, so 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?

The description states a specific verb and resource ('Search enriched GitHub user profiles') plus a scoping modifier ('near a latitude and longitude, ordered by geographic distance') that separates it from the plain datasets_github_users_search sibling. It never names that sibling explicitly, so the differentiation is implied rather than stated.

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?

'Use this when location proximity matters' gives a clear selection condition, which is the right trigger for a geo tool. It stops short of naming the non-geo alternative or any exclusion, so it sits at 'clear context, no exclusions' rather than full when/when-not guidance.

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