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

Annotations already declare destructiveHint=true and idempotentHint=true, so the safety profile is covered. The description adds genuinely new context beyond the annotations: a concrete 10240-byte cap and the resulting 413 error, plus the fact that the whole file is overwritten. It stops short of describing recovery or whether overwrites are reversible.

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 tight sentences, front-loaded with the core action, followed by the usage warning and the hard limit. No sentence is wasted and the most important constraint (use sparingly) is prominent.

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 single-parameter destructive tool with annotations covering the safety profile and a fully documented schema, nothing essential is missing. The cap and error behavior close the remaining operational gap.

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% and the schema already documents the single 'content' parameter, including the empty-string-to-clear behavior. The description adds no per-parameter syntax beyond the cap constraint, 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 (replace) and resource (the entire memory file for the calling user), and explicitly contrasts with the sibling agent_memory_append. An agent can distinguish this from the append 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?

Explicitly says 'USE SPARINGLY — append is the safer primary' and names the three conditions that justify replace (drifted memory, stale entries, user-requested clean rewrite). This is textbook when-to-use vs. alternative guidance.

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