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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive), yet the description adds substantial context beyond them: the immutability guarantee that every chunk belongs to the same revision, the two response shapes (value vs value_json/offset/next_offset), Unicode code-point offset semantics, and an explicit prompt-injection warning to treat document text as data.

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?

Front-loads purpose, then usage, then output shape and chunking, then next steps. Dense and largely waste-free, though 'Costs nothing, writes nothing, starts no run' partly restates what the annotations already imply and the paragraph is long.

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 fully documents the return contract (both small-value and chunked forms) and the pagination protocol. Nothing an agent needs to call it correctly is missing.

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 carry the load, and it does: pointer is defined (default empty = whole document, examples /transform and /sources/0, escaping rules ~0 and ~1), and offset/next_offset usage for chunked reads is explained with concatenation order and termination on null.

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 ('Reads the actual immutable registered recipe') and enumerates the content returned (sources, SQL, checks). It also distinguishes itself from list_recipes and clarifies where recipe_id comes from (get_run), so an agent can differentiate it from siblings without opening a schema.

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?

Explicitly routes the agent: 'Use list_recipes for current table revisions, or recipe_id from get_run for the exact executed revision.' It also advises preferring a focused pointer when only one section is needed and outlines the follow-up path via explain_recipe before register_recipe/propose_revision.

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