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

Annotations already declare readOnlyHint, idempotentHint and openWorldHint=false, so the safety profile is covered. The description adds real behavioral context beyond that: it explains a data-provenance distinction (public-web listings vs. partners/endorsements) and discloses that the founding partner roster is currently empty, which prevents the agent from overstating results.

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 short sentences with zero filler, and the resource list is front-loaded so the agent knows scope immediately. The closing sentence about the empty partner roster is terse to the point of being slightly opaque, but it is still efficient.

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 six-parameter, fully optional lookup with no output schema, the definition covers result provenance and a key caveat, but it never explains the shape of returned entries, how partner vs. outbound records differ structurally, or how this tool relates to find_yards and get_yard. Adequate but with visible gaps.

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 description coverage is 100%, so all six parameters (q, limit, state, region, category, waterway) are already documented, including a category slug example. The description adds no additional syntax, format, or interaction rules for parameters, so the baseline of 3 applies.

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?

Opens with a specific verb and an enumerated set of resources: "Find marinas, yards, surveyors, insurers, suppliers." That is far more concrete than the tool name alone. It does not, however, distinguish itself from the sibling find_yards, even though 'yards' is one of its own categories, leaving overlap for the agent to resolve.

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 gives clear guidance on how to present results — outbound 'Find them online' entries must be flagged to the human for verification — which is genuinely useful usage context. It never states when to choose this tool over find_yards or get_yard, nor any exclusions, so routing guidance is only implied.

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