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

Annotations already establish readOnlyHint=true and openWorldHint=false, so the safety profile is covered. The description adds real behavior the annotations cannot: the change can be pending, refused or failed, and the tool surfaces the limits hit plus what Meta reported afterwards. It does not describe what happens for an unknown or malformed id.

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 sentences, both earning their place. The scope is front-loaded ('One change by id'), and the dense list of return facets compensates for the absent output schema without padding.

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?

With no output schema, the description correctly spends its words enumerating return states, and the workflow timing note completes the picture for a single-param read tool. It is slightly thin on edge behavior, such as unknown ids or what an intermediate state looks like, but an agent has enough to invoke it correctly.

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 0%, so the description must carry the param. 'By id' establishes that change_id is the identifier for a single change, which is the key semantic. It adds no format, sourcing, or example beyond that, leaving length and validation rules to the schema.

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 ('One change by id') plus the exact facets returned: whether it was made, is waiting, was refused or failed, what it changed, limits met, and Meta's report. The 'by id' scope implicitly separates it from list_changes, though it never names that sibling, so it stops short of a 5.

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 explicit lifecycle guidance: call after the person confirms something, before declaring it live. That is a clear when-to-use trigger plus an ordering constraint. It omits when-not-to-use and does not name an alternative, such as list_changes for bulk lookups.

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