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

Annotations already supply the safety profile (readOnlyHint=false, destructiveHint=false, idempotentHint=true), but the description adds genuinely valuable behavior beyond them: strict failure on non-existent ids and the id-reuse lifecycle contrasted with session-tombstoned layer ids. It omits permission/auth requirements and any return/confirmation behavior, keeping it short of a 5. Note there is mild tension between the 'removing an already-removed id fails' strictness and idempotentHint=true, though the second call still leaves state unchanged, so it is not a true contradiction.

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 with the core action front-loaded, followed by failure semantics and the id-lifecycle caveat. No filler and no repetition of the title or annotations.

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 simple mutation tool with no output schema and no nested objects, the description covers the action, error behavior, and a cross-tool lifecycle distinction, which is close to sufficient. It stops short of stating permissions, whether the removal is undoable, or what a successful call returns.

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 only 33%: only 'rationale' is documented in the schema. The description clarifies that the target is the annotation id ('by id'), which maps to annotationId, but says nothing about map_id or the rationale/history-label parameter. It adds modest value over the parameter names alone rather than compensating for the coverage gap.

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 ('Drop a previously-placed annotation by id'), making it unmistakably distinct from the sibling add_annotation and from layer-oriented tools like remove_layer. An agent can select it without opening the 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?

The description implies the only valid usage (removing a previously-placed annotation id) and states the failure condition for already-removed or never-placed ids, which is useful context. However, it never contrasts this tool with alternatives such as remove_layer or mutate_map, nor does it state prerequisites like map selection, so routing guidance is only partial.

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