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

Annotations already establish readOnly/openWorld/non-destructive, but the description adds real behavioral context beyond them: which fields are deliberately withheld (phone, street address, coordinates) and that instant quote data is still returned for listings with no purchasable catalogue. That is exactly the kind of edge-case disclosure annotations cannot carry.

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, front-loaded with the action and identifier, with no filler. The instant-quote sentence is mildly tangential to selecting the tool but does carry useful behavioral information, so it 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?

An output schema exists so return structure need not be explained, and the description supplies the privacy scoping and the quote-availability edge case an agent would otherwise have to discover empirically. Only the lack of an explicit relationship to search_traders keeps it from being fully 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?

Schema coverage is 100% for the single parameter, and its description already names 'search_traders' as the slug source, so the description repeats rather than extends the schema. No format, case, or validation detail is added, making the baseline 3 appropriate.

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 ('Return a public directory profile') and identifies the lookup key ('by listing slug'), which is enough to separate it from browse_trades or search_traders. It stops short of explicitly naming the sibling it complements, so it is clear but not sibling-differentiating.

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?

There is no when-to-use statement, no stated prerequisite (e.g. 'requires a slug obtained from search_traders'), and no alternative named for cases where the caller only has a name rather than a slug. The only signal is the input key, which is already implied by the schema.

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