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

Annotations already declare readOnlyHint=true, openWorldHint=false and destructiveHint=false, so the safety profile is covered. The description adds value beyond that by disclosing the returned shape (role and websites per project), which is the only place the return contents are described since no output schema exists. It omits pagination or result-limit behavior, which keeps it short of a 5.

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 tight sentences with zero filler; the scope and return contents come first and the actionable guidance ('Start here to get a projectId') closes. Nothing is repeated from the name or title.

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 zero-param, read-only listing tool with annotations and no output schema, the description covers purpose, scope, returned fields, and its role as the entry point. Only minor gaps remain (pagination/result limits), which are not critical for correct invocation.

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 nothing for the description to disambiguate and it cannot mislead about inputs. Baseline 4 for a no-parameter tool is 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 ('List'), an explicit resource ('the signed-in user's Projects'), and even what each entry carries ('role and websites'). It is clear on its own, though it does not explicitly distinguish itself from near-neighbors like list_sites or list_backlink_submission_projects, leaving that routing to the agent.

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?

'Start here to get a projectId' gives concrete, actionable context: this is the entry-point call whose output feeds downstream tools. It does not name any alternative or a when-not condition, but for a zero-argument entry tool with no direct sibling equivalent, the guidance is strong.

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