madagascar_fetch_source_excerpt

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

With no annotations, the description must carry the transparency burden. It describes a fetch operation (implying read-only), but does not disclose error behavior for invalid source_key, any limits (e.g., rate limits), or that the content is curated. This is adequate for a simple read tool but lacks depth, meriting a mid-range score.

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?

The description is two sentences, front-loaded with the action, and every word is purposeful. The first sentence states the tool's function; the second gives a crucial usage hint. Zero fluff, ideal conciseness.

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?

Given the tool's simplicity (2 params, no output schema, non-nested), the description fully covers what an agent needs: what it does, how to obtain the key, and a default for excerpt length. No ambiguity remains about invocation or expected result.

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?

The schema already covers 100% of parameters with descriptions. The description adds value for source_key by specifying it can be a number, title keyword, or URL fragment from get_sources, which enriches the schema. For max_chars, it adds no extra info, but the overall parameter guidance is clearer than the schema alone.

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?

The description clearly states the action: 'Fetch a short text excerpt from one curated source URL.' It uses a specific verb ('fetch') and resource ('source excerpt'), and distinguishes itself from siblings like get_sources (which lists sources) and search tools. The purpose is immediately obvious.

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?

It provides clear context on how to use the tool: 'Use source_key as a number, title keyword, or URL fragment from get_sources.' This implies a workflow (get sources first), which orients the agent. It doesn't explicitly mention when not to use it or alternatives, but the context is sufficient given the sibling list.

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