docs_lookup

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

No annotations are provided, so the description carries the full burden. It doesn't disclose whether this makes external network calls, whether it can fail when libraries aren't indexed, what happens with queries that have no matches, or whether it modifies any state. The external dependency on Context7 MCP is mentioned but without behavioral caveats.

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 a single clean sentence that states the tool's purpose and value proposition efficiently. It's front-loaded and has no wasted words. Could arguably be improved by adding usage context, but as written it's concise and focused.

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?

For a single-parameter lookup tool with no output schema and no annotations, the description provides the core purpose and what type of content to expect (up-to-date library documentation and code examples). It doesn't detail return format, failure modes, or common usage patterns, but for a relatively simple lookup tool targeting a well-known MCP server, this is in the acceptable range.

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 100% with only one parameter (query). The description provides no additional meaning beyond what the schema declares—it doesn't explain query format preferences, complexity expectations, or how to phrase effective queries. However, with a single self-explanatory parameter and full schema coverage, the baseline of 3 is appropriate since the schema already documents everything.

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 the tool executes a 'documentation lookup workflow using Context7 MCP' and provides 'up-to-date library documentation and code examples.' It has a clear verb (execute lookup) and resource (Context7 docs), though 'workflow' is somewhat vague and it doesn't distinguish itself from sibling tools like synthesize_documentation which might sound related despite covering different functionality.

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?

The description offers no guidance on when to use this tool versus alternatives. It doesn't state when NOT to use it, doesn't mention that synthesize_documentation might be a better fit for generating docs vs. looking them up, and provides no context about when documentation lookup is appropriate in the broader workflow.

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