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

Annotations already declare readOnly/idempotent/openWorld with destructive=false, so the safety profile is covered. The description adds real value beyond that: output units (ft, kt, s, F, mi), that directions are FROM, and that results carry source/freshness metadata  context not derivable from the structured fields.

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?

Front-loaded statement of what the resource is, followed by the workflow pointer, the concrete user-boat example, and a compact units/metadata line. No filler sentences, though the units clause is dense and slightly bolt-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?

With no output schema, the description helpfully discloses that results include source/freshness metadata and specifies units, covering the return-value gap. The remaining omission is that filter parameters (limit, category) are unexplained anywhere, but for a simple read-only listing the description is largely complete.

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 description says nothing about the query object's q/limit/category members, and schema coverage is effectively 0% for these (only q has an inline hint). It does add the notion of a boat id used elsewhere, but the actual input parameters are left to the schema, which under-documents them.

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+resource (a library of boats with published specs) and enumerates the spec fields (LOA, beam, draft, deadrise, etc.), so the agent knows exactly what kind of records come back. It does not explicitly differentiate from the singular sibling get_boat, which is the closest alternative, so it stops short of a 5.

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?

Gives downstream workflow context ("Pass a boat id to conditions/forecast/routes") and names the user's boat, which implies the tool is for discovering boats to feed into those calls. However it never states when to use list_boats versus get_boat, nor when filtering is warranted, so usage is only implied.

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