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

Annotations already declare readOnlyHint, idempotentHint, and non-destructive behavior, so the safety profile is covered. The description adds the covered source set and output shape, but the return shape largely duplicates the existing output schema rather than disclosing new behavioral traits like rate limits or coverage gaps.

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 front-loaded sentences with zero waste: the core action and scope come first, the output shape second. Every clause earns its place.

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 an output schema, 100% parameter coverage, and complete annotations, the description need not explain return values. It is complete for invocation, though it omits sibling routing that would make it fully self-sufficient.

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 the schema already documents ticker, days (default 30), and source. The description reinforces the source list and references 7d/30d windows but adds no syntax or semantics beyond the schema; 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 (Get), resource (AI-scored news sentiment), and scope (NZX company, named NZ financial media), so the agent understands precisely what is produced. It does not explicitly distinguish itself from the close sibling get_announcement_sentiment, which is a real ambiguity, so it falls short of 5.

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?

The description scopes the tool to news media sentiment, which implicitly suggests when to reach for it versus announcement-based sentiment tools, but it never states when to use it, when not to, or names an alternative. Usage is only implied by the source list.

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