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

readOnlyHint=true already tells the agent this is a safe read, so the description's job is to add matching behavior. It adds the dedup-preceding-creation context, but says nothing about matching semantics (substring vs exact, case sensitivity), result limits, or what an empty result implies. Useful context, but the behavioral picture is incomplete.

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 short sentences, no filler, with the capability stated first and the intended workflow second. Every clause carries information an agent can act on.

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 lookup with no output schema, the description covers what it searches and why. Minor gaps remain around result volume and empty-result interpretation, but nothing essential to invoking it correctly is missing.

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 query parameter is fully documented in the schema, so the baseline is 3. The description restates the same matched fields without adding syntax or matching-behavior detail beyond the schema.

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 gives a specific verb and resource ("Search your shortlinks") plus the fields matched (name, URL, description), which is more precise than the tool name alone. It stops short of naming list_links as the sibling it differs from, so an agent must infer that this is the text-query path versus a full listing.

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 second sentence gives a concrete trigger: use it to check whether a link already exists before creating one, which usefully pairs with create_shortlink. It offers no explicit exclusion or alternative (e.g., use list_links to browse everything), so the when-not case is left implicit.

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