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

Annotations already declare readOnlyHint, idempotentHint and openWorldHint=false, so safety is covered; the description adds the useful detail that results are authorization-scoped to the signed-in user and enumerates which attributes come back. It does not mention ordering or result-size limits, which would be the remaining behavioral gaps.

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 sentences, no filler: the capability and its scope come first, then the sibling routing. Every sentence carries distinct information an agent needs.

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 does its job by listing the attributes returned (organization, platform, language) and the access scope. It could be slightly more complete by noting whether the full list is always returned or if there is any truncation, but for a zero-parameter read tool with rich annotations it is close to sufficient.

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 tool takes zero parameters, so there is no parameter semantics to explain and the baseline of 4 applies. Nothing in the description is needed to disambiguate an argument.

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 and resource ("List the websites") and scopes it to what the signed-in user can access, plus the fields returned (organization, platform, language). The second sentence explicitly separates it from get_portfolio and get_site_brief, so an agent can distinguish it from siblings without opening a schema.

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?

Explicitly names the alternatives and the situation that calls for them ("For an overview with status and priorities, call get_portfolio first and get_site_brief per site"). That is clear routing guidance, though it reads as sequencing/complement rather than a hard exclusion, leaving mild ambiguity about whether list_sites should be skipped when an overview is wanted.

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