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

Annotations already declare readOnlyHint=true and idempotentHint=true, so safety is covered. The description adds that the tool takes no arguments and returns 'a list of specifications with their IDs and domains,' providing return-format context beyond the annotations. It doesn't contradict 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 sections (When to use, Parameters, Returns) and front-loaded purpose. It is slightly repetitive (no arguments stated twice) but every sentence contributes to understanding, so minor redundancy prevents a 5.

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 simple 0-parameter list tool with annotations present, the description is complete: it explains what the tool does, when to use it, and what it returns. No output schema exists, but the Returns section provides sufficient information about the response contents.

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?

With zero parameters, the baseline is 4. The description explicitly reinforces 'This tool takes no arguments' and 'This tool has no parameters,' making the parameter semantics clear even though the schema already shows an empty object.

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 clearly states 'Lists all available API specifications (OpenAPI/Swagger) in the workspace' with a specific verb and resource. It distinguishes itself from siblings like spec_by_id by positioning itself as the starting point for discovery, making its purpose unambiguous.

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 'When to use' section explicitly lists scenarios (e.g., discovering APIs, answering 'What APIs do you support?', seeing scope before exploring). It doesn't name alternatives but implies them with 'before exploring further,' providing clear context without explicit exclusions.

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