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

With no annotations, the description carries the full burden and does so: it discloses that data is read from already-recorded positions (no fetch, no waiting), that promoted competitors' positions persist even when they drop out of results, and that rows carry evidence (term count, average position, first seen). It also states the account prerequisite and a recovery path.

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-loaded with the core definition and two-set distinction, and every sentence carries information. It runs slightly long, and the signup/reconnect paragraph is operationally useful but dilutes the core content; still well above the minimum-viable bar.

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?

No output schema exists, so the description must convey return shape and it does: the two sets, the fields recorded for competitors, and the evidence attached to each row. Auth requirements and fallback tools are also covered, leaving nothing material for correct invocation missing.

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 baseline is 3, but the description adds real meaning: it explains the semantic difference between the two result sets and the exact effect of include_observed (adds unpromoted 'candidates' ranked by how often they beat you). Only extension_id's rarity/format beyond 'From list_extensions' is not elaborated.

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 resource (competitors) and scope (measured across every keyword the extension tracks), and immediately frames the payoff ('the tool for deciding who is worth promoting'). An agent can distinguish it from add_competitor/remove_competitor, which mutate the roster this tool reads.

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?

Explicitly names the decision context it serves and the conditional that selects the second result set ('returned only with include_observed'). It also routes the agent to find_listing and get_store_listing for users without an account, which is exactly the alternative-selection guidance expected.

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