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

The annotations already declare readOnly, idempotent, non-destructive, closed-world, so the safety profile is covered. Beyond that, the description adds genuinely new behavioral information: the response is scoped to status and dates only, the reply body is never returned but goes to the recorded email address, and the tool mutates nothing. The final sentence "It changes nothing" largely restates readOnlyHint, which is why this is a 4 rather than a 5.

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 the outcome states and the input requirement front-loaded, which is the right order for a status-check tool. It loses a little to the closing "It changes nothing" restating an existing annotation, but there is no filler or hedging.

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 two-parameter, non-destructive read with no output schema, the description covers what is returned (status plus dates), what is not returned (the reply), and the exact provenance of the required inputs, which is the main failure mode for this call. Only minor operational details, such as how to recover a missing brief number or email, are absent.

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 coverage is 100%, so the schema already documents both parameters with examples and length bounds, making 3 the baseline. The description does add one piece of meaning the schema lacks — that the email must be the one the brief was originally sent with, not just any address — but it repeats the "A-12" example already present in the schema.

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?

Uses a specific verb and resource ("Returns where a brief... stands") and enumerates the possible states: with Nikita, replied, fixed quote sent, free call booked. It also explicitly ties itself to the sibling send_brief, so an agent can distinguish the read-back tool from the sending tool without opening either 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?

Usage is clearly implied and anchored: the tool is the status check for a brief previously sent with send_brief, and the caller must supply the brief number and email "exactly as in send_brief's receipt." It does not state any explicit exclusion (e.g. how far back statuses remain available, or what to do if the receipt is lost), which keeps it short of a 5.

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