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

Annotations already declare destructiveHint=true and idempotentHint=true, and the description reinforces the destructive aspect with 'replacing the previous one' — telling the agent existing content is overwritten. It adds the 1500-character constraint and the daily-plan context, though it says nothing about permissions or failure 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 tight sentences, front-loaded with the core action and constraint, with the usage context following. No wasted words.

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 mutation tool with no output schema, the description plus annotations cover the essentials: what it does, that it overwrites, the size limit, and when to call it. It leaves the active-brain default behavior to the schema, which is acceptable.

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 all three parameters (brain, concept, summary) are already documented. The description restates the 1500-character cap but adds no meaning beyond what the schema provides, 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?

States a specific verb+resource ('Writes the summary of one topic'), and the '(concept)' gloss plus 'replacing the previous one' make the write semantics unambiguous. It doesn't explicitly name the counterpart topic_summary_get, but the set/get naming and the write framing distinguish it adequately.

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 clear context for when to invoke it: 'Used for topics the daily plan lists as missing or out of date,' which ties the call to the daily_plan workflow. It stops short of naming an explicit alternative tool or stating when NOT to use it.

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