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

Annotations already mark this as read-only, idempotent, and non-destructive. The description adds useful behavioral context: it returns ranked alternatives with similarity_score, match_reasons, and key_differences versus the target, and that it discovers candidates from a single seed facility. However, it does not mention the silent-stripping behavior or the absence of a name parameter, which is only disclosed in schema text.

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 and front-loaded with the core use case, example, return shape, and exclusions. It earns most of its sentences, but the inaccurate parameter enumeration adds noise and should be corrected or removed.

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?

With an output schema and full schema descriptions, the tool is mostly self-sufficient, and the description covers usage and exclusions well. But the param mismatch and omission of match_on/exclude_operator leave an agent with conflicting signals that undermine 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?

Schema coverage is 100%, so the baseline is 3, but the description's parameter list actively conflicts with the schema: it says 'facility_id or name' and mentions capacity_mw, while schema explicitly states there is no name param and has no capacity_mw property. It also omits match_on and exclude_operator. This is misleading rather than helpful.

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 identifies the operation: finding similar, nearby alternatives to a single facility the user likes. It gives a concrete example and contrasts itself with score_facility/analyze_site and compare_sites, so an agent can tell exactly what this tool is for.

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?

It states explicit use conditions ('when a user likes ONE specific facility'), provides an example, and gives explicit exclusions with named alternatives ('Do NOT use to score one site... or to compare a known short-list...'). This leaves no ambiguity about when to invoke it.

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