MCP File Compaction

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

With no annotations provided, the description carries the full burden. It discloses key behavioral traits: it's read-only ('without changing the active file'), returns different content based on file status (active vs. cached vs. unsupported), and mentions caching. However, it lacks details on permissions, rate limits, or error handling, leaving some gaps.

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 front-loaded with the core purpose, followed by a bulleted list for returns that efficiently clarifies behavior. Every sentence adds value without redundancy, making it appropriately sized and well-structured.

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 the tool's moderate complexity (single parameter, no output schema, no annotations), the description is mostly complete: it explains purpose, usage, and behavioral nuances. However, it could improve by detailing output structure or error cases, slightly reducing completeness.

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 schema description coverage is 100%, so the parameter 'path' is fully documented in the schema. The description doesn't add any meaning beyond what the schema provides (e.g., no format examples or constraints), resulting in a baseline score of 3.

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 the tool's purpose with specific verbs ('Get a summary', 'checking APIs') and distinguishes it from siblings like read_file by emphasizing it doesn't change the active file. It identifies the resource as 'file's public interface' and explains the scope of what's returned.

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 provides clear context for when to use it ('useful for checking APIs of files you've already worked on'), implying it's for inspection rather than editing. However, it doesn't explicitly state when not to use it or name alternatives like read_file for full content access, which prevents a perfect score.

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