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

Annotations already cover the safety profile (readOnlyHint, idempotentHint, destructiveHint=false), so the description earns credit for going beyond them: it discloses the by_type breakdown, the two distinct counting semantics (actionable_count vs uncategorized_count), and the transfer-exclusion rule that explains why this tool's total can differ from the income statement. That is genuine behavioral context not derivable from annotations.

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?

Front-loaded with the core purpose and organized into Args/Returns blocks that earn their place given 0% schema coverage and no output schema. The 'Phase 115 —' internal release-notes tag is the one piece of noise an agent gains nothing from.

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 read-only analytics tool with no output schema and no schema-level parameter docs, the description supplies formats, defaults, return contents, and the semantic distinction between the two counts. Only edge details (range inclusivity, empty-result behavior) are unaddressed, which is minor.

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 0%, so the description carries the full burden and does so: both parameters get a YYYY-MM-DD format and a concrete default (Jan 1 of current year / today). This is exactly the compensating detail the empty schema lacks, though it does not discuss inclusivity of the range boundaries.

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: 'Get count and total of uncategorized transactions,' plus a one-line intent gloss ('Identifies transactions that need categorization'). It also implicitly separates itself from the income-statement tool by explaining that uncategorized transfers count here but not there. It never names a sibling alternative directly, so it stops short of a 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?

Usage context is implied rather than stated – the 'what's blocking my income statement from being clean?' framing suggests the agent reaches for this when auditing data quality, but no explicit when-to-use/when-not clause or named alternative tool is given. An agent must infer the trigger from the analytics sibling set.

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