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

Annotations already declare readOnlyHint=true and openWorldHint=false, so safety is covered. The description adds real behavioral value by disclosing the return shape: full provider records plus a per-proxy-type matrix of named fields and notes, which is exactly what an agent needs to decide whether to call it.

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?

Front-loaded with the verb and the key constraint, and the field enumeration is dense but informative in one sentence. The trailing 'Same as GET /api/v1/compare' is partly redundant but anchors behavior for API-familiar agents.

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 bounded, read-only comparison tool with no output schema, the description covers inputs, return contents, and safety via annotations. Only the absence of any note on result ordering or error behavior keeps it short of complete.

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% and the single 'slugs' parameter is documented in the schema with an example. The description's '2 to 6' matches the schema's minItems/maxItems, so it adds no meaning beyond the structured fields — 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?

Specific verb (compare) plus resource (providers), with an explicit cardinality bound of 2 to 6. It clearly separates itself from single-provider siblings like get_provider and from list_providers/search_providers without needing the schema opened.

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 2-to-6 constraint implies when the tool applies, but it never states when to prefer this over get_provider, list_providers, or search_providers. Usage is inferred rather than guided.

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