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

With no annotations, the description carries the full burden. It discloses key behavioral traits: returns catalog entries per ARD spec, and when no match, returns referrals and listing instructions instead of an empty answer. This is useful, though it does not mention auth, rate limits, or side effects, which are likely not relevant for a read-only search tool.

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?

Three sentences, each adding distinct value: purpose, output format, and fallback behavior. The most important scoping information is front-loaded. No redundant phrasing, though it could be slightly more compact without losing clarity.

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 single-parameter search tool with no output schema, the description adequately covers purpose, output format, and fallback behavior. It also references the POST /search endpoint for context. Minor gaps like pagination or limits are not critical for such a simple tool.

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 schema already documents the 'text' parameter. The description adds a concrete example ('find an MCP server for weather data') and clarifies it is a natural-language query, which helps the agent formulate effective inputs beyond the schema's minimal description.

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 ('search') and resource ('what Desvela has indexed'), and explicitly differentiates from siblings by mentioning it uses the same index as POST /search. Also clarifies the output is catalog entries per the ARD spec, distinguishing it from crawler_block_test, preflight, and watch.

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 description implies usage through the natural-language query example and the 'same index' reference, but does not explicitly state when to use it versus alternatives or provide exclusion conditions. Siblings have clearly different purposes, so the context is inferable, but there is no explicit guidance.

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