Check for a duplicate

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

Annotations already establish the tool as read-only, idempotent, and non-destructive. The description adds valuable behavioral details beyond that: it matches against canonical URL forms and compares titles against archived titles to detect re-uploads and mirrors. This explains how the check is performed, which is not inferable from structured fields alone.

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 consists of two sentences, with the first posing a direct, purpose-clarifying question. The second sentence adds key matching behavior. No extraneous words; every phrase 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?

Given the tool's simplicity (2 params, no nested objects) and the presence of an output schema and annotations, the description is largely complete. It covers the main behavior and parameter semantics. Minor gaps like return format are handled by the output schema, and safety is covered by annotations. A 4 is appropriate as it leaves some ambiguity about edge cases (e.g., what counts as a canonical match).

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 has no descriptions (0% coverage), so the description must compensate. It does so by explaining the role of each parameter: 'url' is matched in canonical form, and 'title' (optional) is compared against archived titles. This provides meaning that the schema lacks, though it doesn't deeply elaborate on URL normalization or title matching specifics.

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 states the tool's purpose with a direct question: 'Has this URL already been archived?' It specifies the resource (URL) and the action (checking for duplicates), and distinguishes itself from siblings by detailing the matching logic (canonical form, title comparison) that other search/archive tools likely don't include.

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 the use case: check for duplicates before archiving. It gives clear context for when to use this tool, but does not explicitly mention alternatives or when not to use it. Sibling names like 'search_archive' suggest related but distinct functions, yet no direct comparison is made.

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