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

Annotations already declare readOnly and idempotent hints. The description adds valuable context beyond those: it notes the tool fetches 'latest_version (from GitHub)', exposes rate_limiting fields, and details the exact categories of returned data. It also gives presentation guidance for humans, showing the agent understands the output format. No contradictions with annotations.

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 well-structured with clear headers (# info, When to use, Parameters, Returns, Presentation). It front-loads the core purpose and uses bullet points for readability. Every section earns its place; the presentation guidance is practical and not redundant.

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?

Given that there is no output schema, the description compensates by listing all returned categories and providing formatting advice for human-readable output. It also covers the critical note about rate limiting for agents running loops. This makes the tool fully self-contained for an agent to understand and use effectively.

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?

The input schema has no parameters (0 params), so baseline is 4 as per rubric. The description explicitly states 'This tool has no parameters' and 'takes no arguments', reinforcing the schema. There is no extra parameter semantics to add since there are none.

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 first line clearly states the tool returns 'a comprehensive summary of the swag2mcp runtime' and enumerates specific content (version, configuration, active specs, HTTP client settings, MCP transport, auth methods, mock mode). This is a specific, resource-defined purpose that distinguishes it from sibling tools focused on specs or endpoints.

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?

A dedicated 'When to use' section provides explicit triggers ('user asks what's the current configuration?', 'before calling invoke in a loop', etc.). It gives clear context but does not mention exclusions or alternatives to this tool, which would warrant a 5.

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