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 known; the description adds real value by defining the blast radius — existing monitors survive and only the power to create new ones is revoked. The gap is that it never says whether the new key is returned in the response, which is the single most operationally important fact for a rotate call with no output schema.

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?

The core fact is front-loaded, but the same point is restated three times ('the previous one stops creating monitors', 'existing ones keep working', 'rotating only revokes the power to create new ones'). It is short in absolute terms yet meaningfully redundant.

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 destructive mutation with no output schema, an agent needs to know how the replacement key is obtained and whether the caller must hold the owner token; neither is covered. The blast-radius explanation is complete, but the post-call workflow is not.

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?

One parameter with 100% schema description coverage, so the schema already explains guest_token and its X-Guest-Token usage. The description adds nothing about the parameter, which is acceptable at this coverage level but is the baseline, not above it.

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 and resource ('Rotates the ingest key'), which cleanly separates it from the sibling ingest_key (view/read) and ping_ingest (test). It never names those siblings explicitly, so differentiation relies on the reader inferring it from the verb.

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 only implied: the note that the old key stops creating monitors suggests this is for key-compromise or key-rollover situations, but there is no explicit 'use when' statement, no prerequisites, and no pointer to ingest_key if the agent just wants to view the current key.

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