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

With no annotations, the description carries the full burden. It usefully discloses that reputation is not included and that results are sorted cheapest first, but omits auth/permission requirements, rate limits, and whether the operation is read-only or has side effects.

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-loaded with the comparison purpose and sort order, followed by the limitation and alternative. No filler, though the parenthetical '(new marketplace)' is somewhat tangential.

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 read tool with no annotations or output schema, the description covers purpose, sort order, and fallback routing, but leaves the limit parameter unexplained and does not address auth or return shape. It is adequate but incomplete.

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 description coverage is 0%. The description mentions 'capability' but does not clarify its expected format, and the 'limit' parameter (default 5, max 20) is entirely undocumented. It adds little beyond the schema's property names.

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 states a specific verb ('Compare') and resource ('candidate services for a capability'), plus the comparison criteria ('price and delivery time, cheapest first'). It distinguishes itself from the post_request alternative but does not explicitly differentiate from the search_services sibling.

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 gives a clear when-not condition and names an alternative: 'If no candidate fits, post_request lets people come to you with proposals.' However, it does not state when to prefer compare_services over search_services, leaving some selection ambiguity.

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