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

Annotations already establish that this is a read-only, closed-world call, so the safety profile is covered. The description goes further by disclosing the returned semantics, notably the readsAs vs actsAs distinction and that key id reflects 'the key this call used' - genuine behavioral context, not restated annotation. It stops short of describing the response shape (types, field names) or error behavior, which matters since there is no output schema.

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?

A single front-loaded sentence that leads with the return subject and enumerates fields in a logical order. The nested parentheses defining readsAs and actsAs are dense but earn their space; a bulleted list would be marginally easier to scan.

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 carries the burden of explaining return values and does so competently, including the subtle readsAs/actsAs and SQL-permission fields. It is slightly incomplete on exact field names and value types, but nothing essential for a correct no-argument call is missing.

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 meaning to convey beyond what the empty schema already shows. Baseline 4 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?

Names a specific resource ('this agent seat') and enumerates exactly what identity data comes back: name, role, member id, organization, key id, SQL permission, and readsAs/actsAs. This is unambiguous and cannot be confused with any sibling tool such as read, query, or catalog.

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?

Usage is only implied: the description makes clear this is an identity/introspection call, so an agent will understand it is for discovering its own seat and permissions. It never states when to call it (e.g., at session start, before permission-sensitive operations) or notes that no arguments are required.

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