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

Annotations already declare readOnlyHint, idempotentHint, openWorldHint=false and non-destructive, so the safety profile is covered. The description adds non-obvious provenance context — that the directory excludes repos with bought or farmed stars — which meaningfully affects how much the agent should trust the results.

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 purpose and the anti-pattern guidance before enumerating return fields, and every clause carries information. The trailing list of returned fields is somewhat verbose given an output schema exists, but it is not wasteful enough to penalize more heavily.

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 8 parameters (3 enums), full schema coverage and an output schema present, the description covers purpose, usage trigger, data provenance and result scope adequately. The enumerated return fields partially duplicate the output schema, but nothing an agent needs to invoke the tool correctly is missing.

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% and every parameter, including enums and defaults, is documented in the schema itself. The description only echoes one example query, adding no syntax, format, or interaction detail beyond what the schema already provides, so the baseline of 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?

States a specific verb (find) and resource (open-source GitHub repositories) with a clear qualifier ('real, actively growing') and the underlying data source (semantic search over the RepoAlerts directory). It is clearly distinguishable from siblings like get_repo or trending_repos.

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?

Explicitly says to use it instead of recalling package or repo names from memory whenever the user asks for a tool, library, app, framework or MCP server — a clear when-to-use condition and an anti-pattern to avoid. It does not, however, name sibling alternatives such as find_alternatives, which would make the routing guidance complete.

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