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

Annotations already declare it is a non-read, non-destructive mutation, so the burden is lower. The description adds two non-obvious traits the annotations do not convey: changes apply one field at a time (unmentioned fields stay untouched) and 'this call asks no human', i.e. no confirmation gate before the mutation lands. It stops short of saying whether a rename breaks existing references or how failures surface.

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 short sentences with no filler; the per-call constraint and the enumeration of mutable fields come first, and the no-human-confirmation caveat is a single compact clause.

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 7-parameter mutation tool with no output schema, this covers what can change, how much can change per call, and the lack of a confirmation step. What is left out, scoping by project/environment and behavior on expect_revision conflict, is either patterned consistently across the sibling set or handled by the schema.

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 86%, so the schema already explains size, to, shared_writes, and expect_revision, and the baseline is 3. The description adds one genuine constraint the schema does not encode: only one of the settable fields per call, which matters because the schema itself does not enforce mutual exclusivity.

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 (change) and resource (Volume) and enumerates exactly which attributes are mutable: size, name, shared_writes. It does not explicitly name a sibling, but 'change one thing about a Volume per call' clearly separates it from volume_add, volume_remove, and volume_move by implying in-place attribute modification.

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?

'Change one thing per call' is a usable operating constraint, but the description never names an alternative for cases it excludes (e.g. resizing after deploy, which the schema silently redirects to Ployz Cloud volume resize). The agent must infer when this tool is the right choice versus volume_move/volume_add.

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