theme_screen

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

Annotations already declare readOnly, idempotent, non-destructive and open-world, so the safety profile is covered. The description still adds two things the annotations don't: the authentication requirement and the discovery behavior (empty theme returns the theme listing). It omits how limit affects output or whether results are paginated.

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 short sentences, front-loaded with what the tool offers before the operational notes. Minor waste in the vague 'Needs a login like run_screen' phrasing, but nothing is padded.

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 two-parameter read-only tool this covers the essentials, but with no output schema and no explanation of limit, an agent can't predict result shape (list of theme names vs. ranked companies) or how limiting works. The auth note is a positive but somewhat ambiguous reference to a sibling.

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 must compensate. It explains theme semantics (empty string lists available themes; plausible values are named), which is genuinely useful, but it says nothing about limit (default 25) — whether it caps companies per theme or number of themes returned.

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 resource — pre-built/ready-made screens — and enumerates concrete themes (quality compounders, earnings acceleration, margin expansion, turnaround), which lets an agent distinguish it from the sibling run_screen (custom screens). It never uses an explicit verb like 'run' or 'fetch', so the action is implied rather than stated.

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 one concrete usage rule — call with no theme to list available themes — plus a prerequisite ('needs a login like run_screen'). It does not explicitly say when to prefer this over run_screen for custom criteria, so the alternative-routing is only implied by the word 'ready-made'.

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