Fetch

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

Annotations already provide readOnlyHint, openWorldHint, idempotentHint, and destructiveHint=false. The description adds useful behavioral context beyond those: it returns the full text of exactly one page, and the id is a search-result URL. This is not contradictory with the annotations.

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?

A single, front-loaded sentence with no filler: action, resource, and input all appear immediately. Every word earns its place.

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 one-parameter, read-only tool with an output schema present, the description is nearly complete: it covers input provenance, scope, and result type. The only minor gap is an explicit statement about when to choose fetch over the sibling search tool, but the wording already implies that.

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?

The input schema gives only a bare string field with 0% description coverage, so the description must provide meaning. It does so by clarifying that 'id' is a URL from search, which tells the agent exactly what value to supply. It does not cover edge cases like URL encoding or invalid ids, but for a single input it is sufficiently contextual.

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 a specific action ('Fetch'), a specific resource ('full text of one site page'), and a clear identifier ('its id (a URL from search)'). This distinguishes it from siblings like search (which discovers pages), fleet_list, availability_check, and quote_trip.

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 parenthetical '(a URL from search)' implies the natural usage context: call this after search when you have an id and need a page's full text. However, it does not explicitly state when not to use it or name alternatives, leaving routing partly to inference.

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