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

Annotations already cover the safety profile (readOnly, non-destructive, closed-world), so the description is free to add credential scoping and result ordering. The note that a shared public key yields an empty list is genuinely useful context that prevents an agent from misreading an empty result as an error. It stops short of disclosing any result cap or pagination behavior.

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 short sentences, front-loaded with what the tool returns, followed by the one caveat an agent needs. No filler and nothing repeated from annotations or schema.

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 tool with no output schema, the definition covers scope, ordering, and the empty-result edge case. The remaining gap is that it does not hint at what a booking record contains, which the absent output schema leaves entirely undocumented.

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 per-parameter meaning to add and the baseline of 4 applies. The description correctly adds nothing spurious about inputs.

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 resource and scope: bookings belonging to the current sign-in, returned newest first. It also implicitly distinguishes itself from booking_status by naming that sibling as the route for a different credential context.

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?

Gives a concrete when-not condition (shared public key returns nothing) and names the alternative to use instead (booking_status). The primary when-to-use case is conveyed by the scope phrase 'through this same sign-in' rather than stated outright, so it stops short of full explicit routing.

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