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

Annotations already declare openWorldHint, non-readOnly, non-idempotent, so the safety bar is lower; the description still adds real context beyond them by disclosing that the listing becomes public and that Faceabot will measure and potentially recommend the server. It stops short of saying whether submission triggers moderation, how long measurement takes, or what happens on duplicate submission.

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?

Two sentences front-load the action and outcome, followed by a compact concrete example. Every element serves a purpose, though the inline JSON example adds length that a shorter param hint could partly cover.

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 4-param write tool with full annotations and full schema coverage, the description covers what the tool does and what happens to the submission. Since there is no output schema, it could still say what the caller receives back (an id? a status?) and whether re-submission creates duplicates given idempotentHint=false.

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%, so a 3 is the baseline; the worked example goes beyond the schema by showing that 'name' is a human display title ("Receipt OCR") rather than an identifier and that 'description' is a short functional summary. That resolves ambiguity the bare char-limit descriptions leave open.

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 and resource: 'Add a public MCP server YOU operate to the catalog', and adds the downstream effect that Faceabot measures and recommends it. The 'YOU operate' emphasis implicitly separates it from search/discovery siblings like find_capability, though no sibling is named explicitly.

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 ownership constraint ('a server YOU operate') implies who should use it, but the description never states when to use it versus find_capability, check_reliability, or save_tool_to_toolbox, nor any exclusion such as 'do not submit servers operated by others'. Usage must be inferred.

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