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

Annotations declare readOnlyHint=true, and the description adds meaningful behavioral context: the `teammates_agents` grouping is gated on `allow_team_actions`, so only openable agents appear. It also explains the one-row-per-recipient semantics for `shared_by_me` and the empty result for solo users. This goes beyond the annotation and helps the agent understand the data shape and access implications.

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?

The description is detailed but well-organized: it front-loads the purpose, then provides a compact return schema, then explains the semantics of each group. Every sentence adds value, though the inline schema is somewhat dense. It is longer than strictly necessary but justified by the complex return structure.

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-parameter read-only tool, the description is nearly complete: it explains the return shape, the grouping, the access gating, and the empty case. It does not explicitly state that no input is required, but the empty schema already conveys that. The only minor gap is not describing any pagination or limits, but that is not critical for this tool.

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 has zero parameters, so the schema provides no parameter semantics. The description compensates by thoroughly explaining the return structure and the meaning of each field group, which is the relevant semantic content for a no-parameter tool. Baseline 4 is appropriate because there are no parameters to document.

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?

The description clearly states the tool lists team-shared agents and distinguishes three categories: teammates' agents, agents shared with the caller, and agents shared by the caller. It uses specific verbs and resource terms, and the detailed return structure makes the purpose unambiguous. It also differentiates from sibling tools like list_agents and list_teammates by focusing on shared-agent visibility.

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 explains what the tool returns and the gating condition (`allow_team_actions`), which implies when it is useful: when the caller needs to see openable teammates' agents or shares. It does not explicitly state when not to use it or name alternatives, but the context is clear enough for an agent to select it appropriately.

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