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

Annotations already declare readOnlyHint, idempotentHint and destructiveHint=false, so safety is covered. The description adds genuine behavioral value by stating the return shape ('YoY diffs with added/removed lines and word count trends'), which goes beyond the structured fields.

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 tight sentences, purpose front-loaded, then return shape, then usage triggers. No filler or restatement of the title.

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?

An output schema exists, so explaining return values in detail is unnecessary, and the description covers scope, sections and return type. It is essentially complete, though it could note that only NZX-listed companies with multiple annual reports are applicable.

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, type and compare. The description lists section types but omits the schema's chairman/ceo/esg/audit_opinion options and says nothing about the compare parameter, so it adds little beyond what the schema provides.

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 and resource with scope: 'how a specific section of annual reports ... has evolved across years for a company,' and enumerates the covered sections. It implicitly separates itself from single-read siblings like read_annual_report_section, but never names any sibling to make the distinction explicit.

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 'Use when asked about...' sentence gives clear triggering contexts (risk disclosure changes, governance evolution, remuneration policy changes, reporting change over time). It supplies no when-not conditions and does not name an alternative tool for adjacent questions.

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