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

Annotations already declare readOnlyHint, idempotentHint, openWorldHint and destructiveHint=false, so the safety profile is covered. The description adds beyond that: the api:read scope requirement, the response payload (headlines, posts, sources, times, app_url). With no output schema, disclosing the return shape is genuinely extra value.

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?

Two sentences, front-loaded with what the tool returns and immediately followed by input provenance and format. The auth requirement is relegated to a parenthetical at the end but is short enough not to be wasteful.

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 one-parameter read-only tool with no output schema, the description covers resource scope, input format/provenance, return contents, and auth scope. Only minor gaps remain, such as ordering or volume of returned news and behavior for an invalid ID.

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 0%, so the description must carry the parameter meaning, and it does: it states the ID comes from get_opportunities and repeats the 'mo_' + 32 hex format. That fully compensates for the missing schema description, though it adds no further semantics such as what happens on an unknown or malformed ID.

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 description states a specific verb+resource: news matched to one Today's Market opportunity card. Scoping to a single opportunity_id implicitly separates it from get_news_feed and get_news_headlines, though it never names those siblings explicitly, so the differentiation is inferred rather than declared.

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?

It helpfully says the opportunity_id comes from get_opportunities, which is real usage guidance for obtaining the input. It gives no guidance on when to prefer this over get_news_feed, get_news_headlines, or get_opportunity_detail, leaving the choice implicit.

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