Read one rendered literature figure

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

With readOnlyHint=true and openWorldHint=true already declared, the description adds genuine value by disclosing session behavior: 'Images are obtained inside the governed publisher session; browser cookies and profile state are never returned.' This privacy/session context goes beyond what annotations provide.

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, dense paragraphs with no filler. Core function is front-loaded first, then workflow, then the privacy note. Every 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?

Complete for a read tool with a clear prerequisite, explained index semantics, and disclosed session behavior. No output schema exists, so the return-type statement covers that. Minor gaps: no failure/timeout behavior, but complexity here is well handled.

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 bears the burden. It explains figure_index well ('zero-based figure index', and 'For a PDF or SI URL, the index is the zero-based PDF page'), but wait_ms and timeout_seconds receive no explanation beyond self-descriptive names and defaults. Partially compensates for low coverage but not fully.

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 — 'Return one HTML figure or one rendered PDF page as multimodal content.' It clearly distinguishes itself from sibling literature_read (text extraction) by focusing on figure/PDF content, and the workflow implies this tool complements rather than duplicates literature_read.

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 explicit sequencing: 'Call literature_read first, inspect figures and figure_extraction, then pass the zero-based figure index here.' Also clarifies index semantics for PDF/SI URLs. It lacks an explicit 'do not use when X' exclusion, but the prerequisite workflow is unambiguous.

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