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

Beyond the annotations (readOnlyHint=false, destructiveHint=false), the description discloses that this is a plan-capped operation that can be refused with 402 LIMIT_REACHED at the per-business cap, and that it is an additive write acting as the user's confirmation. That is exactly the operational context an agent needs before mutating state.

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, each carrying distinct information: what it tracks and by which keys, the confirmation precondition, the failure mode, and the Space scoping. Nothing is repeated from the schema and the constraint most likely to cause misuse is placed early.

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 nested-body mutation with no output schema, the definition covers the two things that matter most: authorization/confirmation semantics and the plan-cap rejection path, plus Space binding. An agent can decide and call correctly without further probing.

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 coverage is 100%, so the baseline is 3. The description adds value by naming the accepted identifier kinds (website/domain, page link, name) that map onto the nested body fields, and it clarifies that space_id is a one-call override rather than a session change — slightly reinforcing what the schema already states.

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 ("Track a competitor of a business") and enumerates the acceptable identifiers (website, ad library page link, name), which lets an agent pick it over list_competitors or get_competitor. It does not name sibling tools like suggest_competitors or untrack_competitor outright, so differentiation is inferential rather than explicit.

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?

"Adding one IS the person's confirmation, so only call this when the user has chosen this competitor" gives an explicit precondition plus an implied prohibition on speculative/autosuggest use. It also routes Space handling explicitly: use set_active_space to switch, or pass space_id to override for this one call.

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