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

Adds real behavioral context beyond the annotations: what each result contains (bio, location, company, followers, hireable, top 3 repos), that the exact query and total are returned, cursor pagination via next_cursor, and that the call is free. It also explains the non-read-only side effect (role_id logs the search and marks people seen), which reconciles with readOnlyHint=false. Slightly short of 5 only because rate/limit behavior is left to the schema.

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?

Front-loaded with the core matching semantics and alternative routing, with zero filler sentences. It is a dense single paragraph rather than cleanly segmented, which makes it slightly harder to scan for a 10-parameter tool.

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?

No output schema exists, yet the description covers return contents, the echoed query, total, and pagination cursor usage. Combined with the role_id side-effect explanation, an agent has everything needed to call this 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 coverage is already 80%, but the description adds genuine meaning: query words must all match GitHub-side so keep it to one to three, location may be a region with a top-100 read, and role_id excludes already-seen people unless include_seen. That goes beyond the field-level schema text.

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 (search GitHub profiles) and immediately defines the matching surface: name, login and bio. It also explicitly contrasts itself with find_people_behind_repos and search_candidates, so an agent can route between them without reading schemas.

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 concrete when-to-use guidance ('roles where profiles say more than repos', 'a location constraint') and names the alternative plus the condition that selects it ('for engineers, mining the contributors of seed repos ... is often stronger'). This is explicit routing, not inference.

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