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

Annotations already flag destructiveHint=true and openWorldHint=true, and the description correctly aligns with them rather than contradicting. It adds two non-obvious behaviors the annotations cannot express: credentials are held server-side (no auth plumbing needed by the caller) and mutations are two-step preview-then-confirm, which is corroborated by the confirmationToken parameter.

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 short sentences, front-loaded with the resource and followed by the two operationally important facts; nothing is padded. It loses a point only because the opening sentence duplicates the title instead of spending those words on purpose.

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 an 11-parameter destructive proxy with no output schema and a dense family of sibling endpoints, the description omits what the tool actually returns, which HTTP method maps to which operation in practice, and how it differs from sd_targets_extended. The credential and confirmation notes are valuable but do not close the selection gap.

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% across all 11 parameters, so method, fetchAll, maxResults, queryString, and confirmationToken semantics are already documented. The description adds no parameter-level meaning beyond the schema, so the 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 sentence is a verbatim restatement of the title ('Amazon Ads: sd/targets API') and never supplies a verb describing what the call does — query, create, or update Sponsored Display targets is only inferable from the schema's method enum. It identifies the upstream endpoint but does nothing to distinguish it from the adjacent sd_targets_extended, sd_negative_targets, or sp_targets siblings.

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?

No when-to-use guidance and no routing against alternatives, despite a crowded cluster of near-identical target tools (sd_targets_extended, sd_negative_targets, sp_targets, sb_targets). The only procedural note is 'Mutations require preview and confirmation', which is workflow, not tool selection.

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