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

With no annotations, the description carries the burden well: it discloses that items need a grid-unique key while queries do not, that embeddings must be 1-2048 floats from a single model per grid, and that the response deliberately omits emb. It does not cover permissions, error behavior, or write irreversibility, which keeps it short of a 5.

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-loaded with the endpoint and core action, then packed with dense parenthetical constraints. Every clause is informative, though the run-on second half is dense enough to slow scanning.

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?

An output schema exists, so return values would not strictly be needed, yet the description still clarifies the reply (id and key, not emb). Combined with the key/query semantics and embedding rules, an agent has enough to call it correctly; only failure modes and grid-permission context are absent.

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, and it does: key is explained as an item-vs-query discriminator with uniqueness and example format, and emb is explained with its float range and the one-model-per-grid constraint. Both parameters gain meaning not present in the bare schema.

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?

Opens with a concrete verb+resource ('add a node') and immediately distinguishes the two node kinds (item vs query) that this endpoint creates. An agent can tell it apart from update_node, delete_node, and get_node without opening any 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?

Usage is implied rather than stated: the notes about when an item gets a key and when a query does not make the intended contexts inferable. There is a routing hint toward get_node for embeddings, but no explicit when-to-use/when-not guidance relative to siblings like update_node or create_edge.

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