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

Annotations already declare readOnlyHint=false, idempotentHint=false, destructiveHint=false, and openWorldHint=true, so the write/non-idempotent nature is covered structurally. The description adds real value beyond that: the 'WRITE tool' label, the plan tier requirement, and the auth model (authorized Sonar account or API key with write scope), which the agent cannot infer from annotations.

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?

Front-loads the 'WRITE tool' qualifier and then packs prerequisites and auth into two further sentences with little waste. Slightly dense, but every sentence carries actionable information (effect, precondition, plan, auth).

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 still covers purpose, preconditions, plan gating, and auth, which is what an agent needs to invoke it correctly. It doesn't state what happens on a duplicate/pre-existing competitor (relevant given idempotentHint=false), a minor gap for a 4-param mutation.

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 100%, so parameters are fully documented at the schema level and the baseline applies. The description reinforces the store/product relationship ('same store as the competitor') but adds no syntax or format detail beyond what the schema already states for store, store_id, product_id, and country.

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 (adds/tracks) and resource (a competitor app under a Sonar product) with the downstream effect (keywords and rankings tracked alongside the product's own app). This cleanly distinguishes it from sibling sonar_track_app (own app) and sonar_remove_competitor (the inverse).

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 clear preconditions: the product must already have its own app linked in the same store as the competitor, plus the Indie plan and authorized-account/write-scope requirements. It stops short of naming the relevant sibling alternatives (e.g., create the product first via sonar_create_product), so it's context-rich but not fully routing.

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