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

Annotations declare destructiveHint=true and idempotentHint=false, and the description adds real behavioral context beyond them: it clarifies nothing is actually sent to the recipient and that recording is separate from billing. It does not warn that repeated calls create duplicate records (non-idempotency) or describe permission requirements.

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?

Three short sentences with zero filler; the mutation marker and the core resource statement are front-loaded, and each following sentence adds a distinct fact (no send, billing alternative, endpoint).

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?

No output schema exists, but the fields parameter is self-describing and the description covers purpose, side-effect semantics, and the billing companion. It omits duplicate-creation risk and return shape, minor gaps for an 8-parameter create 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?

Schema description coverage is 100%, so body, subject, type, received_at, senders, receivers, and matter_id are all self-documented, and the description's 'optionally on a matter, with who it was from and to' only cursorily echoes them. Baseline 3 is appropriate since the schema carries the load.

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 (Record) and resource (phone call or email on Clio's communication log) with the 'WRITE:' prefix flagging mutation. The description clearly separates it from clio_list_communications and other list-style siblings without needing the schema.

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?

Explicitly clarifies 'This only records it: Clio sends nothing' and routes time-billing to clio_create_time_entry, which is a genuine when-to-use-this-vs-alternative pointer. It stops short of saying when to prefer clio_create_note or how to avoid duplicate records, so it's strong but not exhaustive.

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