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

Annotations already declare destructiveHint=true and idempotentHint=true, but the description adds substantive context: store fetches stop, recorded history is preserved, re-adding restores charts, and positions continue being observed via existing searches. It also discloses the authentication prerequisite with a concrete login command, which is exactly the kind of operational detail annotations cannot carry.

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 action is front-loaded in sentence one, followed by consequences and then auth requirements in a logical order. The explanation of search-derived position observation is slightly wordy but earns its place by preempting a surprising behavior.

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 3-parameter mutation with no output schema, the description covers the side effects, reversibility, and auth requirement well. It does not say what a successful call returns (confirmation shape) or what happens with an unknown external_id, which keeps it short of full completeness.

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?

With 67% schema coverage, external_id and extension_id already point to their source list tools and store has an enum. The description adds no parameter-level meaning beyond that, so 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?

The first line states a specific verb and resource ('Stop tracking a competitor for an extension') with the scoping entity included. It is trivially distinguishable from add_competitor and remove_keyword by name and action. No ambiguity about what the tool does.

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 'Stop tracking' framing and the note that re-adding restores charts make the add/remove boundary clear implicitly. However, it never explicitly names add_competitor as the inverse operation or states when removal is inappropriate, so the routing guidance is contextual rather than explicit.

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