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

Annotations already establish readOnlyHint=true and openWorldHint=false, so safety is covered. The description adds genuinely non-derivable behavior: funds lacking a figure for the period are excluded and the response reports how many were dropped and why. This is useful context 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?

Compact, front-loaded with the primary concept ('the AfricanMutualFunds board') before the qualifiers. The parenthetical default is efficient. Slightly dense but no wasted sentences.

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 no output schema, the description covers the ranking basis, defaults, category scoping, and the omission/counting behavior. Missing detail on return shape and pagination is minor for a read-only ranking tool whose safety profile is already asserted by annotations.

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 67% with two enums carrying their own values. The description adds meaning for period (default ytd, the board's ranking basis) and category (all-vs-one selection), but says nothing about limit or the 250 cap. A baseline 3 fits when the schema does most of the parameter work.

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+resource: a league table where mutual funds are ranked on a return. It clarifies scope (all funds or one category) and the ranking basis. It stops short of naming siblings like get_mutual_funds or get_mutual_fund_market_summary, so differentiation relies on inference.

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 is implied by the 'across all funds or within one category' framing and the default ytd period, but there is no explicit when-to-use-this-vs-alternative routing. An agent cannot directly tell why it would pick this over get_mutual_funds or get_mutual_fund_market_summary.

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