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

Annotations already cover the safety profile (readOnlyHint, idempotentHint, non-destructive), and the description adds substantial context beyond them: Free-key one-day publication delay, the locked/unlocksAt partial payload for younger briefs, an error when nothing is published, quota cost of one call, and that a rejected argument costs nothing. This is exactly the behavioral detail annotations cannot convey.

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?

Purpose is front-loaded, then routing, then a labelled 'Parameters:' block, then a labelled 'Behavior:' block. Dense but zero filler, and every clause (quota, lock window, error case) earns its place.

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?

An output schema exists so return values need not be explained, and the description still covers the remaining gaps an agent needs: publication delay, partial-payload locking, empty-state error, and quota cost. Nothing material to correct invocation is missing.

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 baseline is 3, but the description adds meaning beyond the schema: DAILY is stated as the default covering the last UTC day, WEEKLY adds 'the coming week's events' (the schema only says 'the week ahead'), and locale is framed as selecting the same brief's language edition (zh/en/ja). It does not add syntactic or format detail the schema lacks, so it stays just above baseline.

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 states a specific verb+resource ('Get the latest brief'), defines what it actually is ('AiSeek's own summary of a period's changes, grouped by section, each item linking to its page'), and explicitly distinguishes it from list_changes, get_topic, and search_changes. An agent can select this tool without opening any 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?

It gives explicit when-to-use ('Use it for a digest') and names three alternatives with the conditions that route to each: 'for the raw newest-first list use list_changes, for a subject get_topic or search_changes.' Nothing is left to inference.

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