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

Annotations already declare readOnly, idempotent, non-destructive, and closed-world, so the safety profile is covered. The description contributes the fallback behavior (no team/league yields Premier League), which the agent needs to predict output without arguments.

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?

Three short sentences, purpose and scope front-loaded, examples placed to drive selection, and the default stated last. No filler; each sentence 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?

A read-only, zero-required-parameter tool with fully documented schema and clear annotations; the description accounts for the no-argument case and typical queries, so an agent has everything needed to invoke it correctly.

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 100%, so baseline is 3, and the description adds real value by disclosing the default behavior when neither team nor league is supplied (defaults to Premier League). It doesn't add format or matching semantics beyond the schema, but the default is behavior the schema doesn't carry.

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 (latest results) and disambiguates scope: 'for a club, or the last round of a league.' It implies distinction from siblings like formguide_get_fixtures and formguide_get_table, but doesn't name them explicitly, so an agent must infer the boundary.

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?

Gives concrete trigger examples ('how did Chelsea get on?', 'what were the Serie A results?') and states the no-argument default (Premier League). It stops short of routing guidance against siblings such as fixtures or standings, so it's clear context without explicit alternatives.

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