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

Beyond the non-readOnly, non-destructive annotations, the description discloses return values (connectionId, tableName), idempotency behavior (existing connection returns created: false unless sheetName differs), latest-upload read semantics, Excel sheet defaulting, file-type restrictions, and required project roles.

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 front-loaded with the core action and then layers in return values, workflow siblings, edge cases, and permissions. Every sentence carries operational information; there is no filler.

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?

Although there is no output schema, the description explains what the tool returns (connectionId and tableName), the idempotent created: false case, downstream querying, file-type refusal, Excel sheet selection, and permission requirements. That is enough for an agent to call it correctly without opening sibling schemas.

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 coverage is 100%, so baseline is 3. The description adds context for sheetName by explaining that an Excel file yields one sheet and that an existing connection is returned unless sheetName requests a sheet it does not hold, which is behavioral meaning not present in the 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?

The description opens with a specific verb and resource: it creates a SQL queryable connection over an uploaded CSV or Excel file, holding it as one table. It explicitly distinguishes this from fastero_create_connection, which is for databases, and names the sibling tools used on the resulting connection.

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 states when to use this tool (uploaded CSV/Excel files), when not to use it (any other file type is refused; databases use fastero_create_connection instead), and how to proceed afterward with fastero_run_sql, fastero_list_connection_schemas, fastero_create_query, and fastero_save_chart.

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