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

Annotations already carry readOnlyHint and openWorldHint, so safety is covered. The description goes beyond them by disclosing the distinctive failure mode (moved-article error is permanent and includes a new address, so do not retry), which is genuinely useful behavioral context. The enumerated return fields slightly duplicate the output schema, keeping it from a 5.

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 dense, front-loaded sentences: identity/scope first, output fields second, error behavior last. No filler, though the return-field list is arguably redundant given the output schema.

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 single-required-parameter read tool with an output schema and annotations, the definition covers retrieval key, output scope, sibling disambiguation, and the non-retryable error path. An agent has everything needed to call it correctly.

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% and the schema already documents the canonical URL plus the accepted backurl query. The description only restates 'required canonical URL from bbb_news' without adding format or edge-case detail beyond what the schema provides, 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?

States a specific verb (Fetch) and resource (published BBB editorial article), plus the required key (canonical URL from bbb_news). It explicitly distinguishes itself from the sibling bbb_scamtracker_search, so an agent can route correctly without opening either schema.

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 explicit when-to-use (BBB-authored alerts and investigations) and when-not (consumer reports, pointing at bbb_scamtracker_search). It also adds error-handling guidance: a permanent not-found that names a new address should not be retried. Nothing is left to inference.

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