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

The annotations already cover the safety profile (readOnly, idempotent, non-destructive, closed-world), so the description only needs to add context. It does so usefully by disclosing the return contents — score, per-test results, evidence, test date — which is the main behavioral fact an agent needs and is not available anywhere else since there is no output schema.

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?

One sentence, front-loaded with the primary value (the score) followed by the supporting detail. No filler and nothing that could be cut without losing information.

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 one-parameter read tool with no output schema, the description carries the return-value burden well by enumerating what comes back. It is slightly incomplete on edge cases — no-score-yet servers, or not-found handling — but nothing an agent needs to make the call correctly is missing.

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?

There is only one parameter and schema description coverage is 100%, with the schema itself giving the slug/npm-package format example. The description adds no additional meaning about the parameter, so the baseline 3 applies.

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 names the resource (one MCP server) and spells out exactly what is returned: a 0-100 score, per-test results and evidence, and the test date. The verb is implicit in the name 'get_score' rather than stated, but the payload is unambiguous and clearly distinct from siblings like search_servers or is_deprecated.

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?

Usage is only implied: the single required slug_or_package parameter signals that this is a lookup for a specific, already-identified server. There is no explicit statement of when to call this versus search_servers (to find a server) or is_deprecated, and no mention of what happens when a server has no score yet.

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