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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint=false, so the safety profile is covered by structured data. The description adds context about the shape of the payload, most usefully clarifying that 'persona' means 'its standing instructions' and noting that sensitive contact fields (email, WhatsApp) and capability toggles are returned. It does not say what happens for a missing or unauthorized agent id, which is the main remaining behavioral gap.

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?

One sentence, front-loaded with the verb and resource, followed by the returned field list with a helpful inline gloss for 'persona.' Nothing is wasted, though the field enumeration is long enough that a slight structural break (scope vs. returns) could have improved scanning.

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 describing return values and does so by enumerating the main fields. For a one-parameter read tool this is essentially complete; only error/empty-case behavior is unaddressed.

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?

There is a single parameter and schema description coverage is 100%; the schema already documents agent_id as coming 'from list_agents.' The description adds no further meaning about the parameter, so the baseline 3 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?

The description opens with a specific verb and resource ('Read one agent') and immediately enumerates the fields returned, so an agent knows exactly what this tool fetches. It contrasts implicitly with list_agents by saying 'one,' but never names or explicitly distinguishes itself from siblings like get_agent_conversation or update_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?

Usage is only implied: 'Read one agent' plus the schema note that the id comes 'from list_agents' suggests the list-then-fetch pattern, but the description itself states no when-to-use conditions and no exclusions versus sibling read tools. There is no guidance on what to do if the id is unknown or the agent does not exist.

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